Boat hull



BOAT HULL Original Filed May 2, 1966 5 Sheets-Sheet 1 I 1 VENTOR.

Jan. 16, 1968 D MORTRUDE 3,333,333 I BOAT HULL Original Filed May 2, 1966 5 Sheets-Sheet 2 5 I INVENTOR.

Jan. 16, 1968 A. D. MORTRUDE I 3,363,598

BOAT HULL Or ginal Filed May 2, 1966 5 Sheets-Sheet 3 IJVETOR.

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United States Patent 3,363,598 BGAT HULL Albert D. Mortrude, Pompano Beach, Fla., assignor to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Continuation of application Ser. No. 546,771, May 2, 1966. This application July 17, 1967, Ser. No. 654,007

22 Claims. (Cl. 114-665) This is a continuation of application Ser. No. 546,771, filed May 2, 1966.

This invention relates to boats generally, specifically to an improved boat hull.

In the past many proposals have been made relating to various improvements in the design of boat hulls. Such proposed improvements can be generally divided into two groups one of which includes improvements relating to decreasing the resistance of the hull to move through or over the water while the other group includes those improvements relating to increasing the directional stability of the hull while so moving through or over the water.

Heretofore, attempts to achieve both goals (reducing the resistance to movement of the boat hull through the water and obtaining maximum directional stability) have not been successful since the designs for the hulls in such instances were at most a compromise weighted toward the particular performance characteristic most desired.

For example, in order to reduce the frontal resistance to the movement of the boat hull, it is desirable that the hull be designed to plane. The ordinary flat bottom type hull is an example of a planing type hull; that is, a boat with such a hull, as it moves forward, tends to climb to the top of the water from a displacement position to a full planing position. However, among other disadvantages, a flat bottom type hull lacks directional stability.

The most conventional type of bull presently employed is but a modification of the fiat planing hull and is of the V or round bottom type. While the planing performance of such a boat has not been improved over the planing performance of the flat bottom design, there are advantages in such a design in that a softer ride is permitted because of the shock absorbing and wave flattening qualities of the bow. Further, in comparison to the flat bottom design, directional stability has been added by the V or the rounding of the bottom.

The mere substitution of a V or round bottom configuration for a fiat bottom in a hull usually results in some considerable loss of planing performance because the particles of water which strike against the leading portion of the planing surface do not strike at a simple angle with respect to such a planing surface but rather strike at a compound angle which is determined generally by the angle of the keel with respect to the water and the sharpness of the V or roundness of the hull, as the case may be. The particles of water striking against such V or round bottom boats are directed outwardly somewhat transversely to the keel of the hull. As a consequence the lifting action of the water is decreased and the planing performance is reduced.

Further, even though the stability of a V or round bottom hull is greater than that of a fiat bottom hull, the stability is not considered to be suflicient in situations where the hull has to pass through or over waves which are at an angle other than perpendicular to the direction of travel of the hull or Where the boat is placed in a sharp power turn. In each of these instances the hull has a tendency to side slip or roll over and capsize. This tendency, which is a normal characteristic of such V or round bottom hulls, is accentuated by such factors as the sharpness of the turn, the power applied in the turn as well as the and more 3,363,598 Patented Jan. 16, 1968 height and angle of approach of the waves through which the hull passes.

In an attempt to improve directional stability various types of multiple-keel hulls have been proposed. In such hulls two or more parallel keels are provided each of which may be of the V or rounded bottom type. How ever, such hulls are seldomly capable of planing and present another disadvantage of relatively high frictional resistance with respect to the water. That is, because the multiple keels are usually displacing water under all operating conditions, the surface Wetted by the water increases greatly causing a correspondingly greatly increased frictional resistance therebetween.

Therefore, a primary object of this invention is to provide an improved boat hull which has a construction of such a nature whereby planing occurs with a minimum of frictional resistance and whereby maximum stability and riding qualities are achieved.

Another object of this invention is to provide an improved boat hull which will quickly change from a displacement position to a planing position upon forward motion of the boat.

A further object of this invention is to provide an improved boat hull which includes means for increasing, during such conditions of operation which so warrant, directional stability thereof.

Other objects and advantages of this invention will become apparent when reference is made to the following description and accompanying drawings wherein:

FIGURE 1 is a side elevational view of a boat hull constructed in accordance with the teachings of this in vention;

FIGURE 2 is a bottom view of the boat hull shown in FIGURE 1;

FIGURE 3 is an elevational view of the transom of the hull taken generally on the plane of line 3-3 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 4 is an elevational view generally of the bow of the hull taken on the plane of line 4-4 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 5 is a generally cross-sectional view taken transversely of the hull on the plane line 55 of FIGURE 2 and looking in the direction of the arrows;

FIGURE 6 is a side elevational view of the boat hull of FIGURE 1 illustrated in a position closely approximating the position assumed by said hull when maximum power is applied to the boat hull from a standing or at rest condition in the water;

FIGURES 7 and 8 are side elevational views of the hull of FIGURES 1 and 6 respectively illustrating positions closely approximating the position assumed by said hull shortly after the full or maximum power start of FIGURE 6 and the full cruising position; and

FIGURE 9 is a fragmentary bot-tom view of the boat hull of FIGURE 1 illustrating a highly desirable wateraerating condition produced by the hull during certain operating conditions.

The boat hull as disclosed and claimed herein may, of course, be constructed of various materials and by any of many methods known to those skilled in the art. For example, the hull may be constructed as by fabrication with individual wood planks suitably secured to an inner frame, or, it could be entirely or partially molded from plywood. However, since the precise method or material employed forms no part of this invention, the hull, hereinafter to be described in detail, will be considered, for purposes of clarity, to have been molded in one piece from some suitable plastic material and/or fiberglass.

Referring now in greater detail to the drawings,

, FIGURES 1 and 2 illustrate a boat hull 10 having a transom 12, how 14 and sides 16 and 18. The sides 16,

18, transom 12 and bow 14 are formed so as to generally blend with a hull bottom 24) which is of a V-like configuration close to the bow end 14 and continues to assume more of a shallow or modified V-bottom configuration as it approaches the stern or transom 12.

The hull 16, as seen in, for example, FIGURES l, 2 and 4 has a substantially straight keel line 22 which blends with the stem line 24 of the bow 14, Further, as seen in FIGURES 2 and 3, the transom 12 may be provided with a cut-out-like portion 26 in order to accommodate an outboard engine.

The bottom 2% of the hull it is provided with strakes 2S and 36 which extended from the stern to the bow 14 so as to meet as at 32. Since it has been assumed that the hall is molded, strakes 28 and 30 are therefore formed to be an integral part thereof. This, of course, would be preferable so that no separate means of securing the strakes to the bottom of the hull would be necessary. As seen in FIGURES 1, 2, 3 and 4, the strakes 23 and 30 respectively have laterally extending surfaces 34 and 36 and additionally have vertically extending surfaces 38 and 4h. Each of the lateral surfaces 34 and 36 progressively increase in width from a minimum as at 32 to a maximum as at the stern or transom end 12 (FIGURE 3). As is best seen from FIGURES 1 and 4, the lateral surfaces 34 and 36 of the strakes 28 and 30, even though substantially horizontal, have a gradual rise from the horizontal toward the bow end 14.

In addition to the strakes, the hull bottom 20' has provided thereon a generally triangular or delta surface 42. The delta surface, as best seen in FIGURE 2, has a leading apex 44 situated at the keel line 22 at a point which is generally midway between the ends of the hull. Ideally, apex 44 is merely a point on the keel line 22. Therefore, as viewed in the side elevation of the hull (FIGURE 1) it can be seen that the delta surface 42 contains a continuation of the keel line 22 and is also substantially horizontal.

The sides of the delta surface 42 terminate in vertically disposed surfaces 46 and 48, respectively, which extend to join the bottom 20' of the hull. As seen in FIGURES 1 and 2, the vertical side surfaces 46 and 48 are inclined with respect to the keel line 22 and taper in width from a maximum at the transom to a minimum at point 44. Preferably, the end 50 of delta surface 42 as Well as the respective ends 52 and 54- of the strakes 23 and 30- terminate so as to be a continuation of the outer surface of the transom 12.

The invention as herein disclosed also contemplates the provision of a sponson on each side of the hull. For example, as seen in FIGURES 1, 2 and 4-, sponson 56 is formed ideally so as to start from a point 58 on side 16 of the hull and then to gradually extend downwardly as it progressively extends toward the stern of the hull. In one embodiment of a hull constructed in accordance with this invention which was successfully tested, the length of the sponson, starting from its forward-most point 58 and measuring to its end surface 60, was between one quarter and one third of the entire length of the hull.

As best illustrated in FIGURE 4, it can be seen that sponson 56 is formed to have diverging outboard and inboard surfaces 62 and 64, respectively, which form a V-like configuration. The inboard surface 64, in cooperation with bottom hull surface between the strake 2t} and the sponson 56, generally, forms a channel-like passageway 66. Preferably, the outboard surface 62 joins a generally laterally extending surface 68 which may also start at point 58 and extend to sponson end surface 60 in a manner so as to exhibit a profile when viewed in the side elevation (FIGURE 1) generally approximating that of the sponson 56 or, as illustrated may extend to the transom 12. A second sponson is similarly provided on the other side of the hull and said second sponson as well as all elements related thereto are identified with like primed reference numerals.

As was previously stated, attempts in the past to achieve the goals of reducing the resistance to movement of the boat hull and yet obtain maximum directional stability have not been successful. However, a boat hull as contemplated by this invention provides in combination, a plurality of features which combine to produce both a substantial reduction to the resistance of movement of the boat hull through the water while at the same time providing maximum degree of directional stability not only in instances where the boat hull is passing through or over relatively calm water, whether it be in a turn or in a straight line, but also in such instances as where the boat is required to pass through rough waters such as may be incurred during periods of high wave formations.

When the boat hull is in an a t-rest condition in the water, the position of the water line with respect to the other components of the hull is illustrated generally by the line indicated at 70 of FIGURE 1. It will be noted that at this time the sponsons 56 and 56' are wetted and have a portion thereof submerged. However, still with regard to FIGURE 1, when the hull is operating at a condition of full cruise or a full running position, the level of the water line with respect to the other elements of hull is illustrated by the line generally indicated at 79a.

In view of the above, it can be seen that there is a tremendous reduction of the area of the hull that is wetted as between the two conditions of standing still within the water and at a condition of full cruise or full running.

A was previously mentioned, one of the ways of reducing the resistance of the boat to move through the water is by designing the hull so as to cause it to be more on top of the water instead of passing through the water. It has been found that the delta surface 42 provides this characteristic to the boat hull. That is, for purposes of illustration, FIGURES 6, 7 and 8 illustrate sequentially the position of the boat hull from a standing full power start (FIGURE 6) through an intermediate position (FIGURE 7) to the full cruise position (FIGURE 8). The position of a boat hull as illustrated in FIGURE 6 was obtained from a test conducted on a particular successful embodiment of the invention wherein an outboard motor, was employed and maximum power was applied almost instantaneously while the boat hull was in a standing position in the water. The almost instantaneous power application caused what may be referred to as cavitation near the stern causing the stern to dip into the water more deeply while raising the bow end 14 as illustrated. Subsequently the boat went through various intermediate positions, one of which is illustrated by FIGURE 7, and finally obtaining the full cruise position of FIGURE 8 It is approximated that the total elapsed time of approximately one and one half seconds transpired between the application of the full power, as illustrated in FIGURE 6, to the attainment of the full cruise position of FIGURE 8. This relatively short elapsed time especially when combined with the adverse conditions of having maximum weight loaded at the stern end of the boat hull is attributable prirnarily to the delta surface 42 which may be referred to as a delta planing surface. As previously described, the delta planing surface 42 is generally triangular starting from an apex or point 44 and expanding laterally to a surface of substantial width at its end 59. Consequently, any tendency to draw the stern of the boat hull downwardly because of cavitation or similar phenomena, is quickly overcome by the planing surface 42 which causes the boat hull to, with any attending forward motion, quickly climb towards the top of the water,

It should be noted that the delta planing surface does have the vertically disposed side edges 45 and 48 which are at a relatively shallow angle with respect to the keel line 22 thereby offering very little frictional resistance to the movement of the boat through the water.

In addition to the delta planing surface 42, additional surfaces which are somewhat similarly disposed as the delta surface 42 are provided by the laterally extending surfaces 34 and 36 of strakes 28 and 36. Just as the delta planing surface 42 has its forward-most point in the form of an apex and increases in width towards the stern of the boat hull so do each of the surfaces 34 and 36 in that they have an ever increasing lateral width starting from their point of juncture 32 and extending towards their respective ends 52 and 54.

Unlike planing surface 42, the laterally extending strake surfaces 34 and 36 are somewhat upwardly inclined, as previously described, and is illustrated by, for example, FIGURES l and 4, so that the surface 34 and 36 tend not only to function somewhat as a flat bottom boat but also tend to trap air into the water flowing thereunder so as to further aerate the water thereby reducing any frictional drag which might otherwise exist. Accordingly, in view of the above, it can be seen that surfaces 34 and 36 combine with the delta planing surface 42 to create lift at precisely that portion of the boat hull where it is most effective for obtaining planing action of the hull.

The strakes 28 and 30, as well as the delta planing surface 42, provide additional functions which enhance the directional stability of the boat hull not only in conditions of straight line motion through the water, but also under conditions of sharp turns and even while passing through waves or choppy water. This is acheieve-d because of the vertically directed surfaces 38 and 40 on the strakes 28 and 30, respectively, and vertically directed surfaces 46 and 48 formed in connection with the delta planing surface 42.

For example, directional stability is provided by the vertical surfaces 38 and 40 as well as surfaces 46 and 48 during such periods of operation as when the boat hull is moving in a generally straight line direction because the water passing by such vertical surfaces is serving to prevent lateral movement of the hull within the water. Further, whenever the boat hull is experiencing a turn, whether it be sharp or shallow, the vertical surfaces 36', 45B and 46, 48 on the outer side of the turn serve to prevent the stern end of the boat from experiencing a side slip in situations where the degree of turn may be extremely sharp. The strake on the outer side of the turn may actually be lifted out of the water; however, in such situations the side surface associated with the delta planing surface and located on the outer side of the turn, will still be within the water and function to prevent side slipping of the hull. This condition of sharp turn as compared to normal forward straight line motion is illustrated primarily in FIGURE 4 by the lines 7012 and 76c with line 700 diagrammatically illustrating the position of the water line relative to the boat hull during any sharp turn maneuver. Line 70b in FIGURE 4 corresponds to line 70a of FIG- URE 1 illustrating the normal full cruise operating position of the boat relative thereto.

As previously stated and as illustrated by the various figures, the bow end of the boat hull is of a relatively sharp V-like configuration which as already explained, becomes somewhat a shallow or modified V bottom hull as the bottom progresses towards the stern. The V-shape of the bow provides a softer riding quality to the boat hull by being able to cut into and through any waves. It should be noted that the strakes 28 and 30 are also tapered as illustrated by the decreasing width of the laterally projecting surfaces 34 and 36 to a minimum width at point 32 thereby providing a minimum area at their respective forward-most ends thereby minimizing any tendency of such strakes at that point to slap or pound against any waves which the bow end of the boat is passing through. In other words, the tapering quality of the strakes at their forward-most ends prevents a rapid increase in buoyancy at that point.

FIGURE 4 best illustrates the shape of the sponsons 56 and 56' which as previously described, also have a V-like configuration. During normal cruise condition with the hull traveling in a generally straight line, the sponsons 56 and 56' are not wetted as illustrated by the relationship of the water line b in FIGURE 4. Directional stability of the hull during this time is, as previously described, provided by the general shape of the hull and the characteristics of directional stability imparted thereto by the vertically disposed surfaces of the delta plane and the strakes. However, in a sharp turn, which is illustrated by the relative position of the water line 700 in FIGURE 4, it is conceivable that one of the sponsons as is illustrated by sponson 56', may become wetted. However, the wetting of the sponson 56' as depicted only serves to further impart directional stability in the turn and prevent side slipping of the hull. Just as the sponson 56 provides directional stability during a sharp turn, it also provides such stability even if the boat hull is traveling in a generally straight line but passing through waves which may be at an angle with respect to the direction of travel. The stability experienced while passing through such waves is achieved in the same manner that the stability is realized during a sharp turn. That is, if one would consider that a portion of line 700 represented a wave, then it becomes evident that a boat hull passing through such a wave will have its sponson cut into the wave and prevent side slip of the hull thereby insuring stability in the side direction. If the boat hull were to pass through waves which are, for example, generally normal to the direction in which the boat is traveling, then because of the V-like configuration of the bow, the boat hull would cut into and through the waves and in so doing each of the sponsons would also cut into and pass through the waves. In such a case, of course, the depth at which the sponsons would pass through the waves would be, to a great degree, dependent upon the velocity of the boat hull and the weight or load carried by the hull. However, in any case, it should be apparent that the sponsons at that time serve to provide at least two desirable functions, one of which is to increase the buoyancy of the hull while going through the wave, and secondly to provide directional stability to the boat hull. Because of the V-like configuration of each of the sponsons, it should be evident that the buoyancy provided thereby is not instantaneous but rather gradual and proportioned to the depth to which the sponsons pass through the water. The V-like configuration provides a degree of softness with respect to increasing buoyancy much in the same manner as does the V-shaped configuration of the bow end of the hull.

In addition to the above, the sponsons provide another important function. Referring primarily to FIGURE 4, it can we seen that the hull bottom 20 and the inboard surfaces 64, 64' of the sponsons 56, 56', respectively, provide the tunnel-like portions 66, 66' which are of a generally arcuate configuration when viewed from the bow end. The provision of such arcuate tunnel-like portions results in the development of a further variable reaction force which serves to cushion and soften the riding qualities of the hull 10 regardless even of the degree to which the hull is caused to jump out of the water as when cutting across a wake at high speeds. As can be seen, for example, by both FIGURES 1 and 4, the bottom portions of the sponsons 56 and 56' are a substantial distance above the keel line and above the water line, as represented by line 79b, during cruising. Accordingly, if the hull should be caused to raise out of the water then fall downwardly thereon, the keel line of the hull strikes the water first. The generally V shape of the bow and hull causes the water thereunder to be thrown generally upwardly and outwardly and the water so thrown impinges upon the arcuate surface of the tunnels 66, 66. Inboard surfaces 64, 64 of the respective sponsons deflect the impinging water downwardly toward the normal water level. This throwing of the water upwardly against the arcuate portrons 66, 66' causes a hydraulic reaction force to be exhibited thereagainst, directed generally upwardly, providing a cushioning effect to the hull and thereby preventing the slapping or pounding sensation often experienced with other hulls when falling back to the water.

4 It can be seen that this would not occur if the bottom portions of the sponsons were not above the keel line. That is, the creation of hydraulic reaction force is primarily dependent upon the keel of the hull entering the water before the bottom portions of the sponsons.

This same phenomenon of hydraulic reaction is also exhibited whenever the hull passes through a wake or other wavy condition such as choppy water surfaces.

It should be apparent that the hydraulic reaction force is a variable one because as the falling velocity of the boat increases, as would occur if the boat were caused to jump a higher distance, the force of the hydraulic reaction also increases because the boat upon coming down into the normal water level causes the water thereunder also to be thrown upwardly and outwardly at greater velocity; since the momentum of the water thusly thrown is proportional to its velocity it then follows that the hydraulic reatcion force would proportionally increase. The hydraulic reaction force should not be confused with the buoyancy that each of the sponsons provide whenever the sponsons are caused to be dipped into or passes through waves.

In every hull design there is, of course, the desire to minimize the area of the hull which is wetted in order to reduce frictional resistance of the water to movement of the boat therethrough. Accordingly, it can be seen that the sponsons act only at the moment or at the condition in which their function is desirable and do not present additional wetted surface during operating conditions wherein neither the added buoyancy nor added directional stability is required.

In order to further reduce any frictional drag or resistance caused by the water on the movement of the boat, the channels 66 and 66, as formed generally between the hull bottom and surfaces 64 and 64, function to draw in air so as to mix it with the water running through the channel during such periods as when the sponsons are either partially or fully wetted. The drawing in of such air causes the water passing through channels 66 and 66 to become aerated or as sometimes referred to burbuled thereby changing what would normally be solid water to a mixture of water and air and thereby reducing the friction of the water passing therethrough and against the hull. This burbuled or aerated effect is diagrammatically illustrated at 72 of FIGURE 9. The aerated water, as will be noted in FIGURE 9, is generally confined after it passes through channel 66, to be between the vertically extending surface 38 of the strake Z8 and the downwardly depending surface 74 of the quad-chine 76. As will be noted best by FIGURES 2, 3 and 5, the quad-chines 76 and 76' are partial extensions of that portion of the boat hull which serves to form the sponsons 56 and 56.

In addition to the aerating action accomplished by the channels 66 and 66, further aeration of the water passing between the surfaces 74, 74' and surfaces 38 and 40 is achieved by the end surface or step 60 formed at the end of the respective sponsons 56, 56. The end surfaces permit air to be drawn in behind such end surfaces when the sponsons are out of the water causing a partial reduction in air pressure there and in turn further causing the water flowing thereby to become aerated or burbuled and thereby reduce the friction of the water against boat hull between the confining surface of the quad-chines 76, 76' and vertical surfaces 38 and 46 of the strakes.

In addition to the features already discussed, it has been found that the sponsons aid in deflecting outwardly and downwardly the spray of water caused by the bow during cruising conditions even though the sponsons are not in the water. Further, whenever the sponsons are in the water, as may occur while the hull is passing through waves, the laterally extending surfaces 68 and 68' function to deflect also outwardly and downwardly the spray of water caused by the respective sponsons.

In view of the above, it should be apparent that a boat hull constructed in accordance with the teachings of this invention has an extremely high degree of directional stability regardless of the direction of travel, degree of turn experienced, or the passing through waves or choppy water. Further, the invention provides a boat hull which even though adversely loaded towards the stern, nevertheless becomes a planing type hull in a very short elapsed time from the application of full power. In addition to the above highly desirable characteristics of the invention, the invention also provides a boat hull which causes a high degree of aerated water to be formed so that the frictional resistance of the water against the boat hull is substantially reduced and the aeration of water is achieved regardless of whether the hull is passing through waves, making a sharp turn or moving in a relatively straight line on a calm surface.

Although only one embodiment of the invention has been disclosed and desecribed it is apparent that other modifications and embodiments of the invention are possible within the scope of the appended claims.

I claim:

1. A boat hull comprising a how, a stern, sides and bottom of single keel, said bottom being of a generally V-shaped configuration at least at the bow and including means for creating a lifting action principally at said stern upon forward motion of said hull, said means comprising a delta sha ed planning surface formed generally along the keel line of said bottom, said delta shaped surface being situated so as to have the apex thereof located forward-most toward said bow so that said delta surface increases in width as said delta surface approaches said stern.

2. A boat hull according to claim 1 including generally vertically disposed side surfaces formed generally on said bottom and depending downwardly therefrom to join said delta surface and form oppositely disposed sides of said delta surface, said oppositely disposed sides being inclined with respect to said keel line so as to converge and meet at said apex.

3. A boat hull according to claim 1, wherein said means for creating a lifting action includes additional surfaces extending generally laterally of said hull so as to assist said delta surface in creating said lifting action at said stern, said laterally extending surfaces being formed on a plurality of strakes which are provided on said bottom and extend for at least a major portion of the length of said hull, each of said strakes including a generally vertically disposed surface extending for at least a major portion of the length of said respective strakes, including a sponson formed on each side of said hull, each of said sponsons starting from a forward-most point on the sides of said hull near said bow and extending rearwardly for a length substantially less than half the length of said hull, each of said sponsons being provided at its rearward-most end with a generally vertically extending end surface in order to cause any water passing by said end surface to become aerated in order to reduce water friction on that portion of the hull bottom extending rearwardly from said end surface to said stern and located respectively between said vertical surfaces of said strakes and said quad-chines.

4. A boat hull according to claim 3, wherein each of said sponsons is provided with an outboard surface and an inboard surface, each of said inboard surfaces cooperating with said hull bottom to form a channel therebetween generally parallel to the keel line of said hull, each of said channels functioning to permit the flow of air therethrough during periods of operation in which said hull is in a normal cruising condition or in a condition causing partial wetting of said sponsons, each of said channels also functioning to permit the flow of water therethrough during periods of operation in which said hull is in a condition causing substantially total wetting of said sponsons, and a generally laterally extending side surface formed on each side of said hull and respectively joining said sponsons at their outboard surfaces, said laterally extending side surfaces extending from said sponsons to said stern, each of said laterally extending side surfaces functioning to limit the height of the water spray resulting from the passage of the respective sponsons through water.

5. A boat hull according to claim 1, wherein said means for creating a lifting action includes additional surfaces extending generally laterally of said hull so as to assist said delta planing surface in creating a lifting action at said stem.

6. A boat hull according to claim 1, including a sponson formed on each side of said hull, each of said sponsons starting from a forward-most point on the sides of said hull near said bow and extending rearwardly for a length substantially less than half the length of said hull.

7. A boat hull according to claim 6, wherein each of said sponsons is formed so as to have a generally frontal V-like configuration which depends downwardly a distance so that said sponsons are normally above the water when said hull is operating in a cruising condition, said sponsons being so positioned as to become wetted when said hull undergoes sharp turns or passes through waves of substantial height.

8. A boat hull according to claim 5, wherein said laterally extending surfaces are formed on a plurality of strakes which are provided on said bottom and extend for at least a major portion of the length of said hull.

9. A boat hull according to claim 8, wherein said laterally extending surfaces increase in width as said surfaces more closely approach said stern.

19. A boat hull according to claim 8, wherein each of said strakes includes a generally vertically disposed surface extending for at least a major portion of the length of said respective strakes.

11. A boat hull according to claim 1 wherein said delta apex is located generally midway between said bow and stern, wherein said means for creating a lifting action includes additional surfaces extending generally laterally of said hull so as to assist said delta planing surface in creating a lifting action at said stern, said laterally extending surfaces being formed on a plurality of strakes which are provided on said bottom and extend for at least a major portion of the length of said hull, each of said strakes including a generally vertically disposed surface extending for at least a major portion of the length of said respective strakes, and including generally vertically disposed side surfaces formed generally on said bottom and depending downwardly therefrom to join said delta surface and form oppositely disposed sides of said delta surface, said oppositely disposed sides being inclined with respect to said keel line so as to converge and meet at said apex, said vertical surfaces formed on said strakes and said oppositely disposed sides combining to provide directional stability to said hull.

12. A boat hull according to claim 11, including a sponson formed on each side of said hull, each of said sponsons starting from a forward-most point on the sides of said hull near said bow and extending rearwardly for a length less than one third but greater than one quarter of the length of said hull.

13. A boat hull according to claim 12, wherein each of said sponsons is formed so as to have a generally frontal V-like configuration which depends downwardly a distance so that said sponsons are normally above the water when said hull is operating in a cruising condition, said sponsons being so positioned as to become wetted when said hull undergoes sharp turns or passes through waves of substantial height.

14. A boat hull according to claim 6, wherein each of said sponsons is provided at its rearward-most end with a generally vertically extending end surface in order to cause any water passing by said end surface to become aerated in order to reduce water friction on that portion of the hull bottom extending rearwardly from said end surface to said stern.

15. A boat hull according to claim 7, wherein each of said sponsons is provided with an outboard surface and an inboard surface, each of said inboard surfaces cooperating with said hull bottom to form a channel therebetween generally parallel to the keel line of said hull, each of said channels functioning to permit the flow of air therethrough during periods of operation in which said hull is in a normal cruising condition or in a condition causing partial wetting of said sponsons, each of said channels also functioning to permit the flow of water therethrough during periods of operation in which said hull is in a condition causing substantially total wetting of said sponsons.

16. A boat hull according to claim 15, wherein each of said sponsons is of a generally arcuate configuration when viewed in side elevation and wherein each of said channels is also arcuate with the forward-most end thereof being inclined upwardly in order to cause air to impinge thereon and force said air at a greater velocity through said channel as said boat hull is operating under normal cruising conditions.

17. A boat hull according to claim 15, including a generally laterally extending surface formed in each side of said hull and joining said sponsons at their respective outboard surfaces, each of said laterally extending side surfaces functioning to limit the height of the water spray resulting from the passage of the respective sponsons through water.

18. A boat hull comprising a bow, a stern, sides and bottom of single keel, said bottom being of generally V-shape configuration at least at the bow, a sponson of generally V-shaped configuration depending downwardly from said bottom at each side of said keel, each of said sponsons starting from a location adjacent said bow and extending rearwardly along said hull for a distance equal to less than half the length of said hull to terminate in a generally vertical step, the bottom edge of each of said sponsons defined along the apex of the V extending generally parallel to said keel and lying throughout the length thereof substantially above the laterally corresponding portion of said keel.

19. A boat hull according to claim 18 wherein said hull further includes a chine running along each side of said keel from a point adjacent said bow to said stern, and wherein each of said sponsons is formed generally along the forward portion of a respective chine.

20. A boat hull according to claim 19 wherein said hull further includes means for creating a lifting action, said lifting means including a flat longitudinally extending surface formed along a bottom strake at each side of said keel between the keel and the respective chine.

21. A boat hull according to claim 20 wherein a generally vertical, longitudinally extending surface is defined at the outboard edge of each of said strakes.

22. A boat hull according to claim 18 wherein the inboard surface of each sponson has an arcuate concave configuration when viewed in transverse cross section and blends smoothly with the adjacent portion of the bottom to define therewith a smooth concave channel at either side of said keel, the forward portion of said bottom along the length of said sponsons having a V configuration with the sides of the V extending upwardly to blend smoothly into said channels so that water thrown upwardly by said bottom forward portion upon reentry of said hull into the water is thrown against the arcuate surfaces of said channels to create a hydraulic reaction force cushioning the downward, reentry movement of the hull.

References Cited UNITED STATES PATENTS 1,826,229 10/1931 Wienen 114-665 2,474,667 6/1949 Harvey 114-665 2,887,978 5/1959 Tritt 9-6 3,117,544 1/1964 Schoell 114-66.5 3,259,092 7/1966 Kara 114-665 ANDREW H. FARRELL, Primary Examiner. 

1. A BOAT HULL COMPRISING A BOW, A STERN, SIDES AND BOTTOM OF SINGLE KEEL, SAID BOTTOM BEING OF A GENERALLY V-SHAPED CONFIGURATION AT LEAST AT THE BOW AND INCLUDING MEANS FOR CREATING A LIFTING ACTION PRINCIPALLY AT SAID STERN UPON FORWARD MOTION OF SAID HULL, SAID MEANS COMPRISING A DELTA SHAPED PLANNING SURFACE FORMED GENERALLY ALONG THE KEEL LINE OF SAID BOTTOM, SAID DELTA SHAPED SURFACE BEING SITUATED SO AS TO HAVE THE APEX THEREOF LOCATED FORWARD-MOST TOWARD SAID BOW SO THAT SAID DELTA SURFACE INCREASES IN WIDTH AS SAID DELTA SURFACE APPROACHES SAID STERN. 